1. Field of the Invention
The present invention relates to a coming-off prevention structure used in a motor.
2. Description of the Related Art
Hitherto, in a disk drive apparatus such as a hard disk drive apparatus, a spindle motor (hereinafter, motor) that rotates a disk is mounted. The disk drive apparatus has a disk, a housing, a stator, an FPC (Flexible Printed Circuit), and the like. The housing has a cover member, a base portion, and the like.
In recent years, there is a demand for further reductions in the thickness and size of the disk drive apparatus. Particularly, in order to further reduce the thickness of disk drive apparatuses belonging to a small size type of 2.5-inches and 7 mm-thick from among disk drive apparatuses, the housing or the motor itself disposed in the housing needs to be made thin.
On the other hand, when the motor itself is thinned, an effect of an external impact on the motor during motor driving is increased. Particularly, when the rotor moves in an axial direction to be distant from the stator due to the impact or the like, a bearing mechanism is not able to sufficiently support a shaft. Therefore, the rotor needs a coming-off prevention structure (i.e., a stopper). However, depending on the coming-off structure, the dimensions in the axial direction of the motor have to be increased, and thus there is a concern that reductions in the size and thickness of the motor may be impeded.
Therefore, a coming-off structure that realizes reductions in the size and thickness of a motor is needed.